<%--
  Created by IntelliJ IDEA.
  User: 86182
  Date: 2020/10/28
  Time: 17:38
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <%
        //往四个域中都保存了相同key的数据    四个域的大小顺序是   pageContext>request>session>application
        pageContext.setAttribute("key","pageContext");
        request.setAttribute("key","request");
        session.setAttribute("key","session");  //session必须先关闭服务器再重启他才会取消
        application.setAttribute("key","application");
    %>
    ${key}
</body>
</html>
